Segmental abrasive wheel



1,469,723 W- W. GREENWOOD SEGMENTAL ABRASIVE WHEEL Oct. 2

Original Filed March 28. 1921 WITNESSES la/a/lace M'rwzzwaoa.

Patented Get, 2, l923.

stares ear-ear ant wettacnw. eannnwoon, or woncns'rnn, MASSACHUSETTS, 'assionon 'ro nonron 7 conranv, or woncns'rnn, MASSACHUSETTS, A, conrona'rron or MASSACHUSETTS.

SEGMENTAL ABR ASIVE WHEEL.

I Appl ation filed March 28,-192L- Serial No. 456,094;

To all whom itmag concern.

Be it known that I, WALLACE W. GREEN- WOOD, a citizen of the United States of America, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented certain new and lid tice to employ a large, solid, sandstone wheel,

which is expensive and when only partly.

worn out must be thrown away. They are,

' moreover, exceedingly heavy and do not permit of any flexibility in their use because 'when they are Worn out or become cracked or must be discarded for any other-reason, the only thing that can be done is to provide another wheel, as the old ones cannot be made to serve any useful purpose in this 'connec-' tion.

:,An etlort has therefore been made to determine whether artificial abrasive wheels.

' with respectto these properties, the conditions for obtaining a short or lon fiber in the ulp or one which is fra ed, as is usually preierred, may be ascertained and duplicated for the various kinds of raw material cine con ere b 6 Sid d (ln account of the raw materials usually being in large pieces, such as logs in the preparation of wood pulp, a wheel is required which has a much larger diameter and greater width of the peripheral surface or face than for-grinding metal, llt would v be exceedingly dificult to make a solid wheel of artificial abrasive which would be suitable for this purpose and the amount of material required would make it very expensive. Consequently, a se mental wheel is necessary and it worn or bro en se ments may be readily replaced in practice, it is much to be preferred. Such wheels have been built up of sections whichwfit together and form a hollowcylinder, the outer or peripheral surface' of which is employed in the grinding action,

but previous constructions do not. provide nor permit of forming a wheel of suflicient width, in which this can be done. The thickness of the segments also has been limited so that sufficient wear is not obtainable before they must be replaced, Grooves or joints between the segments which run parallel to the axis of rotation are apt to chip or splinter the material being ground, and joints which run parallel to the plane of rotation do not grind the-material evenly-at these points and also produce splinters, and in both cases an unsatisfactory pulp results. Moreover,wheels ental type-have involved various of the segm inconvenient methods of clamping the segments to the wheel center or cementing them to it in one Way or another, such as upon iron plates, which were in turn fastened to it.

It is, therefore, an object of my invention to provide a grinding wheel in which the various difficulties mentioned above will be overcome and in which artificial abrasive segments may be clamped directly to the wheel center in a sufiicient number of annu lar rows to give any width of face or diamet-er that may be desired and inwhich the segments may be replaced individually without seriousdelay.

llt is also an-object of my invention to pul vide. forthe use of segments having such shape as to make the joints between them form an oblique angle to their line of con tact with the work; @ther objects will be apgarent' from the following specification. ne form or the type of 'nding wheel in which my invention has i e en embodied is shown by the accompanying drawings, in which: j I 4 Figure 1 is a cross section of the wheel taken, at right angles to the axis of rota; tion;

. Fig. 2 is a cross section of the wheel' through the axis of rotation and along the line-22 of Fig. 1;

Fig. is aside view of the assembled wheel and Fl 4 shows a modification of the wheel in w ich the joints between adjacentsegments are oblique to the plane of rotation.

In accordance with myinvention, ll make a grinding wheel having abrasive segments which form a cylindrical inding surface, a suitable wheel center an adjustable faswill tening means by whichthe segments may be securely held in osition and attached to the wheel center. hese segments consist entirely of bonded abrasive grains and are so shaped as to be helddirectly-by cooperating clamps or other suitable fastenln means. For this purpose I may use a whee 13 of the scents l0 and bolts 14 passing through perforations in the drum and threaded into the wedge-shaped strip. By

tightening the bolts thewedge draws the scents against which it is placed more firmly against the drum and closer together.

In the same manner one or more complete annular rows of segments may be built up and held in place upon the drum. The oints l6 and it? between the segments may e staggered or not as desired. The joint-s ilfl are shown in Fig. 3 as parallel with the axis of rotation and the joints 1? arranged in a zigaagtashion, while in Fig. l have shown all the joints as disposed oblique to a line on the eripheral surface parallel with the axis. he joints between the segments are tilled with a suitable cementing material, which should preferably be insoluble, so that the face of the wheel shall be and remain continuous in its action upon'the work.

This type "of wheel is mounted upon a suitable wheel spindle such as 20 by means of flanges 2i and 22 which serve to hold the rows of segments together and to support the drum concentrically during the grindin operation. In case the flan es are threade upon the spindle as shown in the drawings, the threads for the flan es 211 and 22 should be right and left-hands respectively and so I mounted that the resistance of the grinding action shall tend to force them onto the spindle.

lln constructing a wheel according to the adaptation of my invention which is shown in the drawings, a flange Q1 is threaded upon the spindle 20 after having a ring 23 fastened on its inner side by bolts 2d. The

drum ll is then set over the ring 23 and fastened to the flange 21. by dowel pins 25. Two of the wedge shaped strips 12 are then set upon the drum and loosely engaged by 1 bolts it through suitably spaced holes in the drum. The dovetailedportion 13 of one of the abrasive segments 10 is then slipped between the wedge shaped strips 12 until it butts up against the flange 2i and the bolts 14 are then tightened, drawing the wedge shaped strips downward upon the preparation of. wood pul are preiierre incense drum and securing the se cut-l0 between it and the next similar strip on the opposite side of the dovetail. The wedges will not all be fully tightened until suflicient segments have been set around the drum 1n similar fashion to form a com lete cylindrical surface and similarly c amped by other wedge shaped strips,but after this has been done they may be gradually tightened until all ot the segments are securely held 27, is then threaded upon the wheel spindle v 20 until the outer edge of the flange comes into contact with the edge of the drum andot the abrasive scents, and tightened to hold them in positon as shown.

lit desired, the segments used may ground sons to malre a close and exact tit, one to the other, but this involves a con: siderable amount of care and time. It is therefore preferable in ordinary practice, and equally satisfactory, to leave a narrow space 16 between the segments. and also a narrow spacev 17 between the annular-rows of segments. Then, while the wheel is being constructed a cement may be applied to the sides of each segment" which will come into contact with the others as they are put into position. Or, after the segments have been assembled, a thin fluid cement mixture may be poured into the flssures between them, care being taken that none is permitted to flow upon. the grinding surface.

ltlti The wheel thus assembled is ready tor the shredding ot such material as wood in'the or similar sub stances. Qbviously the w eels maybe used lltl until the segments have been worn down a practically to the wedge shaped strips, when it will become necessary to replacethem; This may be done readily, and moreover with this type of construction, in case an Elli additional segment is broken, as may occur when rough worlr is' being handled-it may be promptly replaced b removing one of the flan es, loosening t e wedges at each -side of t e broken segment, slipping it out from between them and insertin a new segment in its place, tightening th ebolts and replacing the, flanges, when the wheel is again ready for use. p

In my method of construction, various shapes of scents may-be used, but-those forming joints which will come into contact with the work at arr-angle tothe vided for.

raearae T line of contact, The diiiiculties ofsplintering for grinding the work unevenly, which have been hithertoexperienced, are thus avoided.

'lwo shapes of segments are shown in the drawings, in-which these conditions are prosegments in each of'the wheels illustrated'in .ters Patent is than those mentioned. Such-modifications and adaptations, however, are to be considered as comprehendedand included by this'specificationor the appended claims Having thus' described 'my invention, what ll claim asnew and desire to secure by Let- '1. A grinding wheel comprising a cylin drical drum adaptedtobe mounted concenadjustable pressure and replaceably' fasten trically on the wheel spindle, abrasive segments mounted thereon and forming a cylindrical grinding surface, each of said segments having a projectingllug'on an inner portion, and clamping means including a removable wedge to engage said lug with the segment to said drum;

2. lncombination with a wheel spindle, a grindin -.wheel .comprising a cylindrical drum aving perforations therethrough,

of the drum for mounting the same concentrically on the wheel spindle, abrasive segments havinginner cylindrical surfaces fitting the drum and. forming an outer cylindrical grinding surface, and clamps passing throu .the perforations in said drum and It is also to be noted that the clam-ping them in position.

3. In combination with a wheel spindle, a drum, a plurality of abrasive -segments hav ing inner surfaces 'fittin the drum and removably engaging said segments and forming a cylindrical a ad-ing surface, I

means to clamp the segments removably and adjustably on. the drum and' flanges sup.- porting the drum which are removably mounted on the'spindleand e segments. v

- t, In combination with a spindle, a grind: ing wheel thereon comprising-a cylindrical gage the end drum, a plurality of similar abrasive segments forminga cylindrical grinding'surface, each of said segments being provided with a dovetailed projection on its inner portion, wedge shaped clamps removably en aging said, dovetailed projections 'and ad ustgbl fastening said abrasive segments to sai spindle and clamp against the end segments.

5. A grinding'wheel comprising a plural- 'ity of annular 'rows of abrasive segments forming a cylindrical grinding surface, the

joints between the rows of segments being sta gered and each- -joint line forming an forming a cylindrical grinding surface, each separable wheel flanges fastened to the ends rum, and. flanges supporting the drum which are removably mounted on the meg e with a plane perpendicular to the axis of rotation, a wheel center, and ineans for r removably mounting said segments 'upon said wheel center.

joint between the segments being oblique I 

